Process of color photography and composition thereof



P 19431 J. E. KlRBY ETAL I 2,328,652

PROCESS OF COLOR PHOTOGRAFHYAND COMPOSITIONS THEREOF Filed April 18, 1941 BF D DYE 0F PROBABLE Smucrunz \NQ v4531mm v llllll'llli-llllIl-lllllll WAVE LENGTH MILLIMICRUNS INVIENTORS.

James E.K1':rih;14 David. M.MEE]LLEETL Patented Sept; 7, 1943 PROCESS OF COLOR'PHOTOGRAPHY AND COMPOSETION THEREOF James Emory Kirbyand David M. McQueen,

Wilmington, Del., assignors by mesne assignments, to E. I. du Pont de Nemours & Company. Wilmington, Del., a corporation of Delaware Application April 18, 1941, Serial No. 389,244

21 Claims.

This invention relates to color photography.

More particularly it relate to photographic color processes utilizing N-homophthalylamines and to compositions therefor. Still more particularly it relates to dye image formation in photographic elements by color-coupling development in the' presence of N-homophthalylamines and to compositions containing such N homophthalylamines. The invention also relate to novel N- homophthalylamines and to their preparation and incorporation in photographic com sitions.

This invention has for an object the production of new photographic compositions and elements which can be used in th formation of dye images in processes of color photography. A further object i to provide colloid emulsion layers which contain N-homophthalylamines. A further object is to provide new N-homophthalylamines which form dye images of improved tinctorial strength and color upon color coupling development of silver halide images. A still further object is to provide new N-h'omophthalylamines which are non-migratory in colloid layers. Another object is to provide new photographic developer solutions containing novel N-homophthalylamines. Still another object i to provide new chemical compounds, a new use for homophthalic 'anhydride, new dye intermediates and a general advance in the chemical and r lated arts.

It has been found that the N-homophthalylamines, especially N homophthalyl aromatic amines produce dye images of excellent density by color coupling in photographic color processes. To be more specific, it has been found the N- homophthalylamines can be used in processes of producing photographic color pictures with the aid of color coupling development of silver salt images wherein these dye intermediates are present in the developer solutions or in colloid layers of color yielding photographic elements, and that images of excellent dye purity are formed.

The N-homophthalylamines when used in accordance with one aspect of this invention can be dissolved in a suitable solvent, e. g. a water-soluble solvent such as methanol, ethanol and acetone or a dilute aqueous alkali solution which may contain small amounts of said organic solvents and added to a developer solution containing a color coupling developing agent, such as an aromatic primary amino developing agent or a hydrazine. A photographic element containing v finally the silver and any undeveloped silver salts are removed. The resulting film contains a. dye image in a color the hue of which depends upon the .particular N-homophthalylamine and developing agent chosen.

In a. further aspect of the invention, immobile N-homophthalylamines are incorporated in organic colloid dispersions which are then deposited upon a support, e. g. a film base to form a thin layer to carry an image. A practical manner involves dispersing the N-homophthalylamines in an aqueous alkali, usually with the addition of a small amount of a water-soluble organic solvent, and admixing it with the organic colloid Which may be a photographic emulsion containing a reducible silver salt. The dispersions may then be cast or deposited on a suitably subbed film base or an organic colloid layer, a

similar layer, or a water-permeable membrane ments for photographic color processes.

Silver halide emulsions containing one or more of the above color formers or dye intermediates may be worked up in the usual manner. One or more emulsion layers being superposed onone or both sides of transparent supports as desired. The layers may be used for color photography and forsuch purposes the layers are sensitized respectively for diiferent regions of the spectrum. They may also be used in conjunction with the usual cyanine, carbocyanine, pseudocyanine, cyazine, carbocyazine, merocyanine, etc. dyes which are used to extend the sensitivity of silver halide emulsions. a

The development process used in carrying out this invention may be applied either to latent images in an emulsion layer composed of silver halides which have been exposed and which may or may not contain the novel color formers hereof. Or, it may be applied to theresidual unaltered silver salt left where an initial reducedversion of the developed silver image to a silver salt by means of known silver bleaching agents.

An important group of useful N-homophthalylamines have the following general formula:

wherein R is a hydrocarbon radical which may be aliphatic, cycloaliphatic or aromatic, this R may be a primary, secondary, tertiary, iso, or branched chain alkyl, having preferably 8 to 18 carbon atoms; alkenyl preferably 8- to 18 carbon atoms, cycloaliphatic, aralkyl such as benzyl, chlorbenzyl and menaphthyl, and aryl, e. g. phenyl, chlorphenyl, naphthyl, dodecylphenyl. The hydrocarbon radicals attached to the nitrogen atom may be substituted or unsubstituted and contain neutral or salt-forming substituents such as hydrocarbon radicals, halogen atoms, e. g. chlorine, bromine, NHz, NHR, NRR', OH, OR, SOaH, COOH (wherein the Rs constitute hydrocarbon radicals of the same type as R in Formula 1.

The compounds of Formula 1 can be made by reacting at least one mol of homophthalic anhydride with about one mol of a primary amine and recovering the N-homophthalylamine. The reaction is preferably carried out by heating the reactants at a temperature of 100 to 250 C. for a short period followed by isolating the compound by precipitation, extraction, distillation, etc. steps, and purifying it by recrystallization, etc. When the primary amine isn'ot a liquid at model:- ate temperatures, it is desirable to add an inert organic diluent or solvent.- Suitable solvents include hydrocarbons, e. g. benzene, toluene, xylenes, hexane, etc., chlorinated hydrocarbons, e. g. carbon tetrachloride, trichloroethylene, tetrachloroethane, chlorobenzene, etc., ethers, e, g. dioxane, etc.

The invention as is apparent from the above disclosure is not limited to the use of any particular type of primary amine for the preparation of the N-homophthalylamines. On the contrary, any monoor poly-amine containing one or more unsubstituted amino groups can be reacted in similar manner. Aliphatic, cycloaliphatic, or alicyclic, aromatic and hetcrocyclic mono-, diand polyi-amines can be used. In the case of the diand poly-amines, in general about one mol of homophthalic anhydride should be used for each primary amino group. When primary diaminoalkanes or arylenediamines are used, bis-homophthalylamines are formed which are believed to constitute a new class of compounds;

The invention 'will be further illustrated but is not intended to be limited by the following examples, wherein the parts stated are weight:

Example I II o are mixed in a reaction vessel and heated slightly.

The temperature is gradually raised during one dilute aqueous alkaline solutions.

hour to 150 and the water formed in the reaction driven off. After cooling, the solid cake of reaction product is ground up and washed thoroughly with ether. After crystallization from ethanol, a white solid melting at 188-190 C. is obtained. The amount of nitrogen found by analysis is 5.71% whil that calculated for N-homophthalylaniline was 5.90%. The probable formula is The product is soluble in alcohol, acetone, and

A color developer is prepared by dissolving'Z parts of sodium carbonate, 0.1 part sodium sulfite, and 02 part p-aminodiethylaniline hydrochloride in 100 parts water. To this is added 0.25 part of N-homophthalylaniline dissolved in parts aceparts by tone. A film element bearing an image in silver .ferrocyanide in a gelatin layer is immersed in the resulting mixture for 8 to 10 minutes, after which it is washed in running water, bleached in 4% potassium ferricyanide solution and fixed in 25% sodium thiosulfate solution. This treatment removes all silver and silver salts and leaves a clear, bright blue dye image in said layer.

Example 11 Five parts of homophthalic anhydride and 5 parts of 2,5-dichloroaniline are mixed and heated in an open glass vessel on a metal bath. The temperature is slowly raised until the material becomes liquid after whichit is maintained at 140450? C. until the mixture solidifies (approximately 3 hours). During this heating water is given off. The reaction mass is'crystallized from.

ethyl acetate and a white solid melting at 167 C. is obtained. This compound contains 0 22.45% chlorine by analysis,whereas that calculated on the basis of the following formula, N-homophthalyl-2,5-dichloroaniline is 23.20%.

%N 1 Two tenths part of the solid is dissolved in 5 parts 1% sodium carbonate solution containing 1 part methanol and the solution added to 50 parts of an alkaline. p-aminodiethylaniline developer solution. The resulting solution is used to develop a silver bromide image in a gelatin layer of a photographic element. After removing silver and silver salts, a brilliant blue image is obtained.

Example IV Three and five-tenths parts beta-naphthylin 10 parts ethanol.

amine and 4 parts homophthalic anhydride are melted together in an open glass vessel and then heated for one-half hour at a temperature of 180-200 C. At the end of this time the mixture solidifies. Crystallization 'from ethyl acetate yields a white solid of melting point 212-4 C.

Incorporation of this compound, N-homo phthalyl-p-naphthylamine, having the formula:

in an aqueous alkaline color developer solution prepared with i amino-.i-methyl-N-diethylaniline as the active developer constituent yields a blue image in an element when treated after the manner set forth in ExampleI.

Exampie V Four parts homophthalic anhydride' and 6 parts of dodecylamine are mixed at room temperature. The reaction is slightly exothermic. The mixture is then heated at 150-200 C. for one hour, and the resulting solid is crystallized from an ether-petroleum ether mixture and finally recrystallized from methanol. The product melts at 93-95 C. with preliminary softening at 60 C. and contains 4.04% nitrogen. The nitrogen content calculated for N-homophthalyldodecylamine is 4.25%. This compound is dissolved in a mixture of dilute sodium carbonate solution and methanol and incorporated in a gelatino silver chloride-bromide photographic emulsion. After coating on a cellulose nitrate film base, the resuiting film is exposed and developed with paminodiethylaniline developer. A blue dye image is formed in situ with the metallic silver.

image.

Example VI The reaction mixture obtained by heating together 1.8 parts of homophthalic anhydride and, 1.3 parts of octylamine for two hours at 150 C.

group. Of these immobile types, we prefer the N-homophthalylamines substituted on the nitrogen atom with a long chain alkyl group containing at least 8 carbon atoms such as N-homophthalyloctadecylamine and N-homophthalylpara-dodecylaniline.

Additional suitable N-homophthalylamines of the above-described types which can be prepared from homophthalic anhydride and the corresponding primary amines as herein disclosed, in-

' clude the following compounds:

1. N-homophthalyl-alpha-naphthlyamine N-homophthalyl-p-aminomethylaniline N-homophthalyl-p-anisidine N-homophthalyl-paminophenol N-homophthalyl-p-toluidine N-homophthalyl-m-aminobenzoic acid N-homophthalylmetanilic acid N-homophthalyl-m-nitro-p-toluidine.

N-homophthalyl-p-nitroani1ine 10. N-homophthalyl-o-chloroaniline 11. N-homophthalyl-p-aminobiphenyl 12. N-homophthalylbenzylamine 13. N-homophthalylfurfurylamine 14. N-homophthalyl-2-ethylhexylamine 15. N-homophthalylisobutylamine 16. N-homophthalylethylamine 17. N-homophthalyl-n-octadecylamine 18. N-homophthalyl-n-hexadecylamine 19. N-homophthalyl-12-aminostearamide 20. N-homophthalyl-epsilon-aminocaproic acid 21. N-homophthalylcyclohexylamine 22. N,N'-bis-homophthalylethylenediamine 23. N,N bis homophthalylhexamethylenediamine 24.'N,N bis homophthalyldecamethylenediamine 25. N,N'-bis-homophtha1yltrigycoldiamine is dissolved in 20 parts ethanol and incorporated a in 250 parts of a panchromatic photographic gelatino-silver halide emulsion. The resulting emulsion is coated on a cellulose acetate film base and the film exposed and developed with an aqueous alkaline p-phenylenediamine developer. A blue colored image results.

In place of the specific compounds set forth in 'the preceding examples may be substituted 8. large number of other N-homophthalylamines tachment of a long chain aliphatic group which has been exemplified, the compounds may be made non-removable from photographic gelatino-silver halide layers by attaching a polymeric group, or a high molecular weight aromatic 26. N,N-bis-homophthalyl-m-phenylenediamine 27. N,N' bis-homophthalyl-p-phenyienediamine 28. N,N' bis homophthalyl m phenylenediaminesulfonic acid 29. N,N' bis homophthalyl p phenylenedi amlnesulfonic acid 30. N,N-bis-homophthalylbenzidine 31. N,N'-bis-homophthalyldianisidine 32. N,N'-bis-homophthalyltolidine It is characteristic of the products that they are all soluble to a greater or lesser extent in dilute aqueous alkaline solutions and from such.

solutions they may be readily incorporated into the weakly alkaline photographic emuisionwhere they manifest high compatibility. This solubil-' ity in alkali also is of advantage in that they may be incorporated into weakly alkaline photographic developer solutions. Although in general it is not necessary, the compounds may also be dissolved in water-miscible organic solvents such as acetone or alcohol and added to the photographic emulsion or developer as desired.

A comparison between homophthalimide and the N-homophthalylamines of the present invention is shown in the accompanying drawing wherein curve A represents the density of the dye obtained by developin a photographic film element containing a developable silver salt image in a gelatin emulsion layer with p-aminodiethylaniline developer containing homophthalimide, and curve B represents thedens'ity of the dye obtained by developing a similar photographic film element with the same developer containing N-homophthalylaniline. saturation and purity is an unexpected result;

and the incomparably' superior properties of the The great difierence incompounds of the present invention suggest that there is an actual difference in structure between them and homophthalimide. This is entirely probable since it is well known that homophthalimide has the possibility of existing in the form of the isoquinoline derivative.

while the homophthalylamines cannot so exist because of the substituentgroups on the nitrogen atom.

While all the homophthalylamines are of utility in the preparation of color photographic elements, we prefer the homophthalyl aromatic .amines because they yield dyes having higher saturation, greater brilliancy, and purity. Another class of preferred compounds consists of the N ,N'- bis-homophthalyldiamines which are readily prepared by reaction of two molecules of homophthalic acid or homophthalic anhydride with one molecule of a primary diamine. The presence of the two coupling residues in the one molecule of' color former with these compounds is believed to confer enhanced color intensity and brilliance. weight of the bis-homophthalyldiamines results in a resistance to diffusion in gelatin layers. A similar resistance to diffusion is encountered in the homophthalyl polymeric amines such as poly(p-aminostyrene) and its interpolymers, for example, such as are described in British Patent 7 524,996.

The dye intermediates are useful in various types of color processes wherein dye images are produced by color-forming development and azo coupling processes and processes including both color-forming development and azo coupling of the same color formers. conjunction .with various types of reducible silver salt images, including silver halides, such as thechloride, bromide, chlorobromide, chloro-bromo-iodide, etc. images; bleached silver images, i. e. silver ferrocyanide, silver-copper-chloride, silver-chromium-chloride, as well as silver chromate and other water insoluble silver salts. The images formed by the exposure of bichromated gelatine are also reduced by the color-forming developers described above, yielding blue dye images.

The compounds of the present invention are of considerable utility in the preparation of azo dyes. The homophthalylamines' are energetic couplers and couple even with weakly couplin'g diazonium salts such as benzenediazonium chloride. considerably with the diazonium salts chosen, but in general lies between bluish-red.

In place of the specific developing agents described in the above examples can be substituted 9. large number of other color-developing agents containing anunsubstituted amino group. Suitable additional agents are described in U. S! Patents 2,182,815, 2,189,817, 2,191,037 and 2,200,924.

The-silver salt images can also be developed with hydrazine developers in like manner to produce azo dye images. Suitable developers are described in U. S.'Patent 2,220,929.

In addition, a silver halide emulsion layer c'on-' veloped to a silver image and fixed can be treated In, many cases the high molecular The shade vof the dyes obtained varies yellow-orange andv They may be used in with a diazo or tetrazo, etc. saltand'converted into a colored image by the process of U. S. Patent 1,517,049.

The compounds hereof can also be used in photographic color processes involving azo coupling. They couple readily in emulsion layers with diazotized aromatic amines and give azo dye images of good color and strength. The new compounds give azo dyes which are of utility in the arts.

Thesubstitution of a hydrocarbon residue on the nitrogen atom of homophthalimide has been shown to result in greatly improved color obtained upon color development of a silver salt in the presence of such compounds. The dyes thus obtained show greatly improved brilliance and saturation over the unsubstituted homophthalimide itself as is shown by the curves in the accompanying drawing.

Various types of organic colloids can be used as the binding agents for the dispersions or emulsions and colloid layers described herein. Suitable colloids exhibiting high viscosity characteristics and appreciable jelly strength which are compatible with the N-homophthalylamines and can be used as binding agents in place of gelatin include albumin, agar-agar, Irish moss,

2. A photographic element bearing at least one water-permeable colloid layer having dispersed therethrough an N-homophthalylamine which contains in its molecule a radical which imparts thereto fastness to diffusion with respect to said colloid layer while retaining solubility in aqueous liquids.

3. A photographic element bearing at least one water-permeable colloid layer having dispersed therethrough an N-homophthalylaromaticamine. h

4. A photographic element bearing at least one water-permeable colloidlayer having dispersed therethrough an N-homophthalylarylamine.

5. A photographic element bearing at least one water-permeable colloid layer having dispersed therethrough an N-homophthalalkylamine having at least 8 carbon atoms in the aliphatic chain.

6. A photographic element bearing at least one water-permeable colloid layer having dispersed therethrough an N,N'-bis-homophthalyldiamine.

7.v A photographic element bearing at least one water-permeable colloid layer having dispersed therethrough an N-homophthalylamine and a reducible silver salt.

8. An element as set forth in claim 7 wherein said amine contains in its molecule a radicalrespect to said colloid layer while retaining sol ubility in'aqueous liquids.

9. A photographic developer comprising an aqueous solution containing a color coupling developing agent and an N homophthalylamine.

10. A photographic developer comprising an aaaaesa aqueous alkaline solution containing an arcmatic primary amino developing agent and an N-hornophthalylamina 11. A photographic developer comprising an aqueous alkaline solution containing an arcmatic primary amino developing agent and an N-homophthalylarylamine,

12. The process which comprises developing a.

photographic element containing a reducible silver salt image record with a color coupling developing agent in the presence of an N-homophthaylyamine.

13. A process as set forth in claim 12 wherein said amine nucleus contains a solubilizing group 14. The process which comprises developing a photographic element containing a reducible silver salt image record with a colorcoupling developing agent containing a primary amino group in the presence of an N-homophthalyl-arylamine,

15. The process which comprises developing a photographic element containing a reducible silver salt image record with a color coupling developing agent containing a primary amino group in the presence of an N-homophthalylkylamine wherein the aJiphatic'hydrocarbon radical contains at least 8 carbon atoms.

16. The process which comprises developing a -persed therethrough photographic element containing a reducible silver salt image record with a color coupling primary aromatic amino developing agent in the presence oi N-homophthalyianiline 17. A photographic developer comprising an aqueous alkaline solution containing an aromatic primary amino developing agent and Iii-homophthalylaniline.

18. The process which comprises developing a photographic element containing a reducible ,silver salt image record with a color coupling primary aromatic amino developing agent in the presence of N-homophthalyl-m-amino benzoic acid.

19. A photographic developer comprising an aqueous alkaline solution containing an aromatic primary developing agent and N-homophthalyl-m-amino benzoic acid.

. 20. The'process which comprises developing a photographic element containing a reducible silver salt image record with a color coupling primary aromatic amino developing agent in the presence of N-homophthalyldodecylamine.

21. A photographic element bearing at least one water permeable colloid layer having dis- N-homophthalyldodecylamine.

JAMES EMORY KERBY. DAVID M. MCQUEEN. 

